“This is not the time to cast a jocular or feel-good vote for a man whom you may have briefly found entertaining.”

Libertarian presidential nominee Gary Johnson is still making the case that neither Donald Trump and Hillary Clinton are worthy presidential candidates.

Earlier this month, Johnson urged rally-goers at the University of New Mexico, “Don’t vote for Clinton and don’t vote for Trump.” And in a Facebook post published Friday, Johnson said, “If you want to throw your vote away with either Clinton or Trump, that’s something that you will have to live with.”

But in a remarkable statement released Tuesday, Johnson’s running mate, former Massachusetts Gov. Bill Weld (R), broke with Johnson and made a case for Hillary Clinton by urging undecideds to stop Trump while acknowledging Libertarians won’t be able to do so.

The statement begins with a quiet concession of defeat. “Gary and I will carry our message of fiscal responsibility, social inclusion, and smaller government through November 8, and I hope that this election cycle will secure for the Libertarian Party a permanent place in our national political dialogue,” Weld writes.

He notes that while progress is being made toward “breaking the two party monopoly,” the exclusion of third parties from the debates means that “the deck is still stacked against even a credible third party ticket with two proven former Governors.”

Weld then turns to making the case against Trump — a case he says is addressed “to all those in the electorate who remain torn between two so-called major party candidates whom they cannot enthusiastically support.”

Trump is temperamentally unfit, Weld argues. “After careful observation and reflection, I have come to believe that Donald Trump, if elected President of the United States, would not be able to stand up to this pressure and this criticism without becoming unhinged and unable to perform competently the duties of his office,” he writes.

“A serious candidate for the Presidency of the United States must be stable, and Donald Trump is not stable,” Weld continues, going on to compare Trump’s behavior to a child’s.

“When challenged, he often responds as a child might,” he continues. “He makes a sour face, he calls people by insulting names, he waves his arms, he impatiently interrupts. Most families would not allow their children to remain at the dinner table if they behaved as Mr. Trump does.”

Citing Trump’s fearmongering about immigrants, Muslims, and foreign trading partners, Weld notes that “from the beginning of his campaign, Mr. Trump has conjured up enemies.”

“The goal of the Trump campaign, from the outset, has been to stir up envy, resentment, and group hatred,” he writes. “This is the worst of American politics. I fear for our cohesion as a nation, and for our place in the world, if this man who is unwilling to say he will abide by the result of our national election becomes our President.”

To Weld, Trump represents an unprecedented threat — one that prompted him to step “out of the swirl of the campaign” and release a statement specifically denouncing him.

“Not in my lifetime… has there been a candidate for President who actually makes me fear for the ultimate well-being of the country, a candidate who might in fact put at risk the solid foundation of America that allows us to endure even ill-advised policies and the normal ebb and flow of politics,” he writes, before concluding that voters should do what’s necessary to prevent Trump from becoming President.

“This is not the time to cast a jocular or feel-good vote for a man whom you may have briefly found entertaining,” Weld writes. “Donald Trump should not, cannot, and must not be elected President of the United States.”

Weld’s statement doesn’t mention Hillary Clinton once. But by arguing that Trump should be disqualified from becoming President, Weld is making the same type of case for Clinton that House Speaker Paul Ryan (R-WI) is making for Trump — that there are only two realistic options, and one of them is far worse than the other.

UPDATE: Wednesday evening, a Johnson spokesman released a statement arguing that Weld’s denunciation of Trump wasn’t meant as an endorsement of Clinton.

Several web sites and media outlets have seized upon Governor Bill Weld’s statement from a news conference Tuesday in Boston to jump to conclusions that are wishful thinking, rather than reality.

Led by Occupy Democrats, a well-known mouthpiece for the left, the sensationalists and wishful thinkers are re-writing Gov. Weld’s forceful condemnation of Donald Trump into a suggestion that voters should support Hillary Clinton. That is absurd.

The statement did not come directly from Weld, but Weld himself later tweeted that the notion he meant to encourage undecideds to choose Clinton is “false.”